[lttng-tools.git] / src / common / consumer / consumer-metadata-cache.c

/*
 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
 *                      David Goulet <dgoulet@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _LGPL_SOURCE
#include <assert.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <inttypes.h>

#include <common/common.h>
#include <common/utils.h>
#include <common/sessiond-comm/sessiond-comm.h>
#include <common/ust-consumer/ust-consumer.h>
#include <common/consumer/consumer.h>

#include "consumer-metadata-cache.h"

enum metadata_cache_update_version_status {
	METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED,
	METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED,
};

extern struct lttng_consumer_global_data consumer_data;

/*
 * Extend the allocated size of the metadata cache. Called only from
 * lttng_ustconsumer_write_metadata_cache.
 *
 * Return 0 on success, a negative value on error.
 */
static int extend_metadata_cache(struct lttng_consumer_channel *channel,
		unsigned int size)
{
	int ret = 0;
	char *tmp_data_ptr;
	unsigned int new_size, old_size;

	assert(channel);
	assert(channel->metadata_cache);

	old_size = channel->metadata_cache->cache_alloc_size;
	new_size = max_t(unsigned int, old_size + size, old_size << 1);
	DBG("Extending metadata cache to %u", new_size);
	tmp_data_ptr = realloc(channel->metadata_cache->data, new_size);
	if (!tmp_data_ptr) {
		ERR("Reallocating metadata cache");
		free(channel->metadata_cache->data);
		ret = -1;
		goto end;
	}
	/* Zero newly allocated memory */
	memset(tmp_data_ptr + old_size, 0, new_size - old_size);
	channel->metadata_cache->data = tmp_data_ptr;
	channel->metadata_cache->cache_alloc_size = new_size;

end:
	return ret;
}

/*
 * Reset the metadata cache.
 */
static
void metadata_cache_reset(struct consumer_metadata_cache *cache)
{
	memset(cache->data, 0, cache->cache_alloc_size);
	cache->max_offset = 0;
}

/*
 * Check if the metadata cache version changed.
 * If it did, reset the metadata cache.
 * The metadata cache lock MUST be held.
 */
static enum metadata_cache_update_version_status metadata_cache_update_version(
		struct consumer_metadata_cache *cache, uint64_t version)
{
	enum metadata_cache_update_version_status status;

	if (cache->version == version) {
		status = METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED;
		goto end;
	}

	DBG("Metadata cache version update to %" PRIu64, version);
	cache->version = version;
	status = METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED;

end:
	return status;
}

/*
 * Write metadata to the cache, extend the cache if necessary. We support
 * overlapping updates, but they need to be contiguous. Send the
 * contiguous metadata in cache to the ring buffer. The metadata cache
 * lock MUST be acquired to write in the cache.
 *
 * See `enum consumer_metadata_cache_write_status` for the meaning of the
 * various returned status codes.
 */
enum consumer_metadata_cache_write_status
consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
		unsigned int offset, unsigned int len, uint64_t version,
		char *data)
{
	int ret = 0;
	struct consumer_metadata_cache *cache;
	enum consumer_metadata_cache_write_status status;
	bool cache_is_invalidated = false;
	uint64_t original_max_offset;

	assert(channel);
	assert(channel->metadata_cache);

	cache = channel->metadata_cache;
	ASSERT_LOCKED(cache->lock);
	original_max_offset = cache->max_offset;

	if (metadata_cache_update_version(cache, version) ==
			METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED) {
		metadata_cache_reset(cache);
		cache_is_invalidated = true;
	}

	DBG("Writing %u bytes from offset %u in metadata cache", len, offset);

	if (offset + len > cache->cache_alloc_size) {
		ret = extend_metadata_cache(channel,
				len - cache->cache_alloc_size + offset);
		if (ret < 0) {
			ERR("Extending metadata cache");
			status = CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR;
			goto end;
		}
	}

	memcpy(cache->data + offset, data, len);
	cache->max_offset = max(cache->max_offset, offset + len);

	if (cache_is_invalidated) {
		status = CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED;
	} else if (cache->max_offset > original_max_offset) {
		status = CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT;
	} else {
		status = CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE;
		assert(cache->max_offset == original_max_offset);
	}

end:
	return status;
}

/*
 * Create the metadata cache, original allocated size: max_sb_size
 *
 * Return 0 on success, a negative value on error.
 */
int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
{
	int ret;

	assert(channel);

	channel->metadata_cache = zmalloc(
			sizeof(struct consumer_metadata_cache));
	if (!channel->metadata_cache) {
		PERROR("zmalloc metadata cache struct");
		ret = -1;
		goto end;
	}
	ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
	if (ret != 0) {
		PERROR("mutex init");
		goto end_free_cache;
	}

	channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
	channel->metadata_cache->data = zmalloc(
			channel->metadata_cache->cache_alloc_size * sizeof(char));
	if (!channel->metadata_cache->data) {
		PERROR("zmalloc metadata cache data");
		ret = -1;
		goto end_free_mutex;
	}
	DBG("Allocated metadata cache of %" PRIu64 " bytes",
			channel->metadata_cache->cache_alloc_size);

	ret = 0;
	goto end;

end_free_mutex:
	pthread_mutex_destroy(&channel->metadata_cache->lock);
end_free_cache:
	free(channel->metadata_cache);
end:
	return ret;
}

/*
 * Destroy and free the metadata cache
 */
void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
{
	if (!channel || !channel->metadata_cache) {
		return;
	}

	DBG("Destroying metadata cache");

	pthread_mutex_destroy(&channel->metadata_cache->lock);
	free(channel->metadata_cache->data);
	free(channel->metadata_cache);
}

/*
 * Check if the cache is flushed up to the offset passed in parameter.
 *
 * Return 0 if everything has been flushed, 1 if there is data not flushed.
 */
int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
		uint64_t offset, int timer)
{
	int ret = 0;
	struct lttng_consumer_stream *metadata_stream;

	assert(channel);
	assert(channel->metadata_cache);

	/*
	 * If not called from a timer handler, we have to take the
	 * channel lock to be mutually exclusive with channel teardown.
	 * Timer handler does not need to take this lock because it is
	 * already synchronized by timer stop (and, more importantly,
	 * taking this lock in a timer handler would cause a deadlock).
	 */
	if (!timer) {
		pthread_mutex_lock(&channel->lock);
	}
	pthread_mutex_lock(&channel->timer_lock);
	metadata_stream = channel->metadata_stream;
	if (!metadata_stream) {
		/*
		 * Having no metadata stream means the channel is being destroyed so there
		 * is no cache to flush anymore.
		 */
		ret = 0;
		goto end_unlock_channel;
	}

	pthread_mutex_lock(&metadata_stream->lock);
	pthread_mutex_lock(&channel->metadata_cache->lock);

	if (metadata_stream->ust_metadata_pushed >= offset) {
		ret = 0;
	} else if (channel->metadata_stream->endpoint_status !=
			CONSUMER_ENDPOINT_ACTIVE) {
		/* An inactive endpoint means we don't have to flush anymore. */
		ret = 0;
	} else {
		/* Still not completely flushed. */
		ret = 1;
	}

	pthread_mutex_unlock(&channel->metadata_cache->lock);
	pthread_mutex_unlock(&metadata_stream->lock);
end_unlock_channel:
	pthread_mutex_unlock(&channel->timer_lock);
	if (!timer) {
		pthread_mutex_unlock(&channel->lock);
	}

	return ret;
}
Commit	Line	Data
331744e3 JD	1	/*
	2	* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
	3	* David Goulet <dgoulet@efficios.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License, version 2 only,
	7	* as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along
	15	* with this program; if not, write to the Free Software Foundation, Inc.,
	16	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	17	*/
	18
6c1c0768	19	#define _LGPL_SOURCE
331744e3 JD	20	#include <assert.h>
	21	#include <pthread.h>
	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include <sys/types.h>
	25	#include <unistd.h>
	26	#include <inttypes.h>
	27
	28	#include <common/common.h>
	29	#include <common/utils.h>
	30	#include <common/sessiond-comm/sessiond-comm.h>
	31	#include <common/ust-consumer/ust-consumer.h>
c8fea79c	32	#include <common/consumer/consumer.h>
331744e3 JD	33
	34	#include "consumer-metadata-cache.h"
	35
c124970b JG	36	enum metadata_cache_update_version_status {
	37	METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED,
	38	METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED,
	39	};
	40
fe81e5c9 DG	41	extern struct lttng_consumer_global_data consumer_data;
fe81e5c9 DG	42
331744e3 JD	43	/*
	44	* Extend the allocated size of the metadata cache. Called only from
	45	* lttng_ustconsumer_write_metadata_cache.
	46	*
	47	* Return 0 on success, a negative value on error.
	48	*/
	49	static int extend_metadata_cache(struct lttng_consumer_channel *channel,
	50	unsigned int size)
	51	{
	52	int ret = 0;
	53	char *tmp_data_ptr;
53efb85a	54	unsigned int new_size, old_size;
331744e3 JD	55
	56	assert(channel);
	57	assert(channel->metadata_cache);
	58
53efb85a MD	59	old_size = channel->metadata_cache->cache_alloc_size;
53efb85a MD	60	new_size = max_t(unsigned int, old_size + size, old_size << 1);
331744e3 JD	61	DBG("Extending metadata cache to %u", new_size);
	62	tmp_data_ptr = realloc(channel->metadata_cache->data, new_size);
	63	if (!tmp_data_ptr) {
	64	ERR("Reallocating metadata cache");
	65	free(channel->metadata_cache->data);
	66	ret = -1;
	67	goto end;
	68	}
53efb85a MD	69	/* Zero newly allocated memory */
53efb85a MD	70	memset(tmp_data_ptr + old_size, 0, new_size - old_size);
331744e3 JD	71	channel->metadata_cache->data = tmp_data_ptr;
	72	channel->metadata_cache->cache_alloc_size = new_size;
	73
	74	end:
	75	return ret;
	76	}
	77
93ec662e JD	78	/*
	79	* Reset the metadata cache.
	80	*/
	81	static
	82	void metadata_cache_reset(struct consumer_metadata_cache *cache)
	83	{
	84	memset(cache->data, 0, cache->cache_alloc_size);
	85	cache->max_offset = 0;
	86	}
	87
	88	/*
	89	* Check if the metadata cache version changed.
	90	* If it did, reset the metadata cache.
	91	* The metadata cache lock MUST be held.
93ec662e	92	*/
c124970b JG	93	static enum metadata_cache_update_version_status metadata_cache_update_version(
c124970b JG	94	struct consumer_metadata_cache *cache, uint64_t version)
93ec662e	95	{
c124970b	96	enum metadata_cache_update_version_status status;
93ec662e JD	97
93ec662e JD	98	if (cache->version == version) {
c124970b	99	status = METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED;
93ec662e JD	100	goto end;
	101	}
	102
	103	DBG("Metadata cache version update to %" PRIu64, version);
93ec662e	104	cache->version = version;
c124970b	105	status = METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED;
93ec662e JD	106
93ec662e JD	107	end:
c124970b	108	return status;
5b8eb761 JD	109	}
5b8eb761 JD	110
331744e3 JD	111	/*
331744e3 JD	112	* Write metadata to the cache, extend the cache if necessary. We support
c585821b MD	113	* overlapping updates, but they need to be contiguous. Send the
c585821b MD	114	* contiguous metadata in cache to the ring buffer. The metadata cache
331744e3 JD	115	* lock MUST be acquired to write in the cache.
331744e3 JD	116	*
c124970b JG	117	* See `enum consumer_metadata_cache_write_status` for the meaning of the
c124970b JG	118	* various returned status codes.
331744e3	119	*/
c124970b JG	120	enum consumer_metadata_cache_write_status
c124970b JG	121	consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
93ec662e JD	122	unsigned int offset, unsigned int len, uint64_t version,
93ec662e JD	123	char *data)
331744e3 JD	124	{
	125	int ret = 0;
	126	struct consumer_metadata_cache *cache;
c124970b JG	127	enum consumer_metadata_cache_write_status status;
	128	bool cache_is_invalidated = false;
	129	uint64_t original_max_offset;
331744e3 JD	130
	131	assert(channel);
	132	assert(channel->metadata_cache);
	133
	134	cache = channel->metadata_cache;
c124970b JG	135	ASSERT_LOCKED(cache->lock);
c124970b JG	136	original_max_offset = cache->max_offset;
93ec662e	137
c124970b JG	138	if (metadata_cache_update_version(cache, version) ==
	139	METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED) {
	140	metadata_cache_reset(cache);
	141	cache_is_invalidated = true;
93ec662e JD	142	}
93ec662e JD	143
331744e3 JD	144	DBG("Writing %u bytes from offset %u in metadata cache", len, offset);
	145
	146	if (offset + len > cache->cache_alloc_size) {
	147	ret = extend_metadata_cache(channel,
	148	len - cache->cache_alloc_size + offset);
	149	if (ret < 0) {
	150	ERR("Extending metadata cache");
c124970b	151	status = CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR;
331744e3 JD	152	goto end;
	153	}
	154	}
	155
	156	memcpy(cache->data + offset, data, len);
c124970b JG	157	cache->max_offset = max(cache->max_offset, offset + len);
	158
	159	if (cache_is_invalidated) {
	160	status = CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED;
	161	} else if (cache->max_offset > original_max_offset) {
	162	status = CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT;
	163	} else {
	164	status = CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE;
	165	assert(cache->max_offset == original_max_offset);
331744e3 JD	166	}
	167
	168	end:
c124970b	169	return status;
331744e3 JD	170	}
	171
	172	/*
	173	* Create the metadata cache, original allocated size: max_sb_size
	174	*
	175	* Return 0 on success, a negative value on error.
	176	*/
	177	int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
	178	{
	179	int ret;
	180
	181	assert(channel);
	182
	183	channel->metadata_cache = zmalloc(
	184	sizeof(struct consumer_metadata_cache));
	185	if (!channel->metadata_cache) {
	186	PERROR("zmalloc metadata cache struct");
	187	ret = -1;
	188	goto end;
	189	}
	190	ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
	191	if (ret != 0) {
	192	PERROR("mutex init");
	193	goto end_free_cache;
	194	}
	195
	196	channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
	197	channel->metadata_cache->data = zmalloc(
	198	channel->metadata_cache->cache_alloc_size * sizeof(char));
	199	if (!channel->metadata_cache->data) {
	200	PERROR("zmalloc metadata cache data");
	201	ret = -1;
	202	goto end_free_mutex;
	203	}
	204	DBG("Allocated metadata cache of %" PRIu64 " bytes",
	205	channel->metadata_cache->cache_alloc_size);
	206
	207	ret = 0;
	208	goto end;
	209
	210	end_free_mutex:
	211	pthread_mutex_destroy(&channel->metadata_cache->lock);
	212	end_free_cache:
	213	free(channel->metadata_cache);
	214	end:
	215	return ret;
	216	}
	217
	218	/*
	219	* Destroy and free the metadata cache
	220	*/
	221	void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
	222	{
	223	if (!channel \|\| !channel->metadata_cache) {
	224	return;
	225	}
	226
	227	DBG("Destroying metadata cache");
	228
331744e3 JD	229	pthread_mutex_destroy(&channel->metadata_cache->lock);
	230	free(channel->metadata_cache->data);
	231	free(channel->metadata_cache);
	232	}
	233
	234	/*
	235	* Check if the cache is flushed up to the offset passed in parameter.
	236	*
	237	* Return 0 if everything has been flushed, 1 if there is data not flushed.
	238	*/
	239	int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
5e41ebe1	240	uint64_t offset, int timer)
331744e3	241	{
04ef1097 MD	242	int ret = 0;
04ef1097 MD	243	struct lttng_consumer_stream *metadata_stream;
331744e3 JD	244
	245	assert(channel);
	246	assert(channel->metadata_cache);
	247
7f725ec5	248	/*
5e41ebe1 MD	249	* If not called from a timer handler, we have to take the
	250	* channel lock to be mutually exclusive with channel teardown.
	251	* Timer handler does not need to take this lock because it is
	252	* already synchronized by timer stop (and, more importantly,
	253	* taking this lock in a timer handler would cause a deadlock).
7f725ec5	254	*/
5e41ebe1 MD	255	if (!timer) {
	256	pthread_mutex_lock(&channel->lock);
	257	}
ec6ea7d0	258	pthread_mutex_lock(&channel->timer_lock);
04ef1097	259	metadata_stream = channel->metadata_stream;
04ef1097	260	if (!metadata_stream) {
fe81e5c9 DG	261	/*
	262	* Having no metadata stream means the channel is being destroyed so there
	263	* is no cache to flush anymore.
	264	*/
	265	ret = 0;
c9b95901 JG	266	goto end_unlock_channel;
	267	}
	268
	269	pthread_mutex_lock(&metadata_stream->lock);
	270	pthread_mutex_lock(&channel->metadata_cache->lock);
	271
	272	if (metadata_stream->ust_metadata_pushed >= offset) {
04ef1097	273	ret = 0;
fe81e5c9 DG	274	} else if (channel->metadata_stream->endpoint_status !=
	275	CONSUMER_ENDPOINT_ACTIVE) {
	276	/* An inactive endpoint means we don't have to flush anymore. */
	277	ret = 0;
331744e3	278	} else {
fe81e5c9	279	/* Still not completely flushed. */
331744e3 JD	280	ret = 1;
331744e3 JD	281	}
fe81e5c9	282
331744e3	283	pthread_mutex_unlock(&channel->metadata_cache->lock);
fdb1cb82	284	pthread_mutex_unlock(&metadata_stream->lock);
c9b95901	285	end_unlock_channel:
ec6ea7d0	286	pthread_mutex_unlock(&channel->timer_lock);
5e41ebe1 MD	287	if (!timer) {
	288	pthread_mutex_unlock(&channel->lock);
	289	}
331744e3 JD	290
	291	return ret;
	292	}